Testing and adjusting apparatus for cord circuits



W. H. HARRISON.

TESTING AND ADJUSTING APPARATUS FOR CORD CIRCUITS APPLICATION FILED FEB. 7, 1920.

Patented. Sept 12, 1922.

2 SHEETS-SHEET 1.

v INVENTVOR. 21 fZf/(Zf/MW W ATTORNEY W. H. HARRISON.

TESTING AND ADJUSTING APPARATUS FOR CORD CIRCUITS.

I APPLICATION FILED FEB.I,1920. A28

2 SHEETS-$HEET 2.

Patented Sept. 12, 1922.

A TTORNEY Patented Sept. 12; lSZZO sr'rss WILLIAM H. HARRISON, or BROOKLYN, NEW You AssreNon TO AMERICAN TELE- lHONE AND TELEGRAPH ooMrANY, A oonronATIoN on NEW YORK.

TESTING AND ADJUSTING APPARATUS FOR CORD CIRCUITS;

Application filed. February '7, 1920. Serial No. 357,068.

To all who m, if may (former 12 Be it known that I, WILLIAM H. HARRI- soN residing at Brooklyn, in the county of Kings and State of New York, have invent ed certain Improvements in Testing and Adjusting Apparatus for (lord Circuit-s, of which the following is a specification.

This invention relates to testing apparatus and more particularly to equipment for testing and adjusting the various apparatus associated with a telephone cord circuit.

One of the principal objects of this invention consists in providing testing equipment which, when connected to a cord circuit, af tords means todetermine whether the supervisory relays associated with the cord circuit function properly under conditions which are either approximately the same or are more severe than those experienced in actual service.

Another object consists in providing adjusting equipment whereby the adjusting of the supervisory relays to meet the desired operating conditions may be done in an efficieut manner.

Other and further objects of the invention taken in connection with the accompanying drawings, Figures 1 and 2 of which when arrz-inged with Fig. 2 to the right of Fig. 1, embody a circuit diagram of the testing and adjusting features of the invention.

Fig. 1 illustrates a circuit diagram of a standard toll cord circuit terminating in the usual front and back plugs P and P which are adapted for insert-ion into the usual line jacks (not shown) that are installed in a switchboard. A direct current supervisory relay 1. and an alternating current supervisory relay 2 are associated with said cord circuit. whereby the said cord circuit may be used to establish a supervised connection either between two long distance toll lines or between a long distance toll line and a toll switching trunk line orother similar trunks. If two long distancetoll lines are connected by inserting plugs P and P into two line jacks (not shown) in which the said toll lines terminate at a switchboard, the alternating current relay 2 may be energized by alternating current whlch may be transmitted over each .orreither of said toll lines. "The circuit containing the direct current supen visory relay 1, which is normallybridged across the said cord circuit, is opened by the operation of marginal relay 3when the cord circuit is used to establish a connection between two long distance tolllines, whereby the loss in transmission due to such bridged relay is prevented. If, however, a long distance toll line is connected by said cord circuit to a toll switching line, over which direct current is transmltted for supervisory pur- 1305685 the alternating current relay 2 may be energized by the alternatin ringing current transmitted over the long distance toll line, and the direct current supervisory relay 1 may be energized by the direct current transmitted over the toll switching trunk line.

In addition to the usual'line jacks special switchboard section in order that the toll cord circuits located in each switchboard section may be connected with the testing or adjusting circuit shown in Fig. 2.

Jacks J and J shown in Fig. 2 and hereinafter designated as control j acks, are connected to jacks J and J and are preferably mounted in the'rear of the switchboard sections wherein jacks J and J appear. In

order that the testing or adjusting circuit may be controlled from the point at which the supervisory relays of the cord circuit to be tested are located, a test set. T is'provided,

the plug P of which may be inserted in the control jacks J 3 or J and the plug P of which may be inserted into lamp ack J or either of the plugs of the toll cord with which said relays are associated maybe injacks J and J are multiplied at each J of an auxiliary circuitwhich is assoserted in either of the jacks'J and J at the switchboard, and plug inserted in either of the control jacks J and J respectively and the plug P inserted in jack J Then by manipulating the keys of the test set T, the operation of the supervisory relays may be observed and suitable adjustments may be made if said relays are not functioning properly.

The test set T comprises keys K K K K*, K, and K. Keys K K K, and K" are preferably of the locking type and the two first mentioned keys are adapted to control the adjustment of the direct current supervisory relays of a cord circuit. Keys K and K are preferably of the non-locking type and together with the keys K and K are adapted to control the alternating current supervisory relay of acord circuit. Associated with the set T is the signal 60 which is used for indicating the action of the relays under adjustment,

Having described generally the circuits and apparatus shown in the drawings embodied in Figs. 1 and 2, the invention may now be made clear from the following description of its operation.

When it is desired to adjust the apparatus of. the cord circuitshown in F 1. the key 6 of Fig. 2 is operated, and completes the following circuit: from ground. lower contact of said key, conductor 7. resistance 5%. through armature 9. field winding: 10 ot motor interrupter M to battery 11'. The depression of key 6 also closes the following circuit: from battery 12. conductor 13. lamp 14, upper contact of key 6, conductor 15, spring 16 to ground. The closing; ot the first-mentioned circuit by the depression of key 6, RHSGS the motor interrupter apparatus M to set in motion, and the closing of the second mentioned circuit provides for the intermittent lighting of lamp 1% which indicates whether or not the interrupter is working properly, and serves as a guard signal in case said interrupter is left running when the circuit is not in use.

Key 17 is now depressed for the purpose of providing a circuit through rheostat 18. whereby the ammeter 19 may be adjusted to the proper current value of an actual line over the following circuit: from grounded battery 20, resistance 21, conductor 22, resistance 23, conductor 24, letthand outer contact of key 17, conductor 25. resistance 26, conductor 27, rheostat 18, conductor 28. outer righthand contact of key 17, through the ammeter 19 to ground. By now adjusting rheostat 18 the current flow over the above traced circuit, which will be indicated by annneter 19, may be regulated as desired.

The circuit is now in condition for testing I the apparatus of a cord circuit.

Test/Tug direct current s'u vo/"vs017 relay.

relay 5. sleeve conductor of said cord. sleeve contacts of plug P and jack 3. sleeve contacts of jack and plug P of key K oi test set T, conductor 31. resist ance 32, closed contact of key K contact of key K conductor 33, tip contacts of plug P and jack J conductor 34, winding of relay 35. conductor 86. winding of marginal relay 8'7, conductor 88, winding of relay 39 to ground. This circuit will cause the operation of relays 30, and 39. The opera tion of relay 3O closes a circuit from battery 29 over its amature and contact which will be described later. The operation of relay 39 will complete an intermitti-int circuit from ground through spring: lb of motor M. couductor 40, armature and contact oi relay $31), conductor 4-1, winding of relay 42 to battery. The relay 42 will be operated intermittently by this circuit. and each time it operates will, complete a circuit from ground through its upper armature and contact over conrh'u-tor 4S, resistance 4 1-. upper back contact and armature ot relay conductor 1:6. upper back contact of rela l7. closed ari'mture or! contact of relay 35, through tip contacts of jack J and plug P closed contact and armature of relay conductor 48, contact of key 49, conductor 50, through one side of coil 52, contact of marginal relay 3. winding of supervisory relay 1, out through the other side o'l coil. conductor 53, lower right hand contact of key 49, ring contacts of plug P and jack J lower contact and amature oi? relay 35, conductor 60. lower armature and back Contact of relay 4-7, resistance 21 to grounded battery 20. This circuit will provide for the intermittent energization of supervisory relay 1. This circuit is of relatively low resistance and the current flow thereover is suflicient to saturate relay 1. The operation of said relay will indicate that it is properly adjusted and that its armature will not stick up under any of the conditions that it is likely to undergo in service. The relay 1 will attract its armature intermittently and close the following circuit: from grounded battery in the cord circuit, filament ot lamp 55. contact and armature of relay 1. conductor 57, through the tip contacts of jack J and plug P winding of relay 58, sleeve contacts of plug P and jack J to ground. R0121. 58 will he *ncrgrived by this circuit and will close a circuit from battery 12. resistance 59. ringcontacts oi jack J and plug P filament of lamp (30. contact and armature of relay 58 to ground. This circuit will cause lamp 60 to light. Thus each time the supervisory relay 1 operates and lights the supervisory lamp 55. the indicating lamp 60 will also be lighted. The flashingof lamp 60 at the proper intervals will indicate that the direct current relay 1 will operate properly under the condition described.

The plug P is left inserted in the ack J closed contact and key l? of: the test set T may now be de pressed to provide for the minimum current condition and the fast operation otdirect supervisory relay 1. l/Vhen the key K is depressed a current path similar to that outlined in connection with the key K will he proviiled, but instead of traversing the key K as previously described, it passes through the lower make contact 01 key K and causes the a1 paratus contained in said circuit to "function as describedabove. An additional current path is also provided, which is similar to the previously described path, to the resistance 32, from which it continues as follows: from conductor 31 of the test set T to the upper contact of key K back over conductor 67, ring contacts of plug P and jack J lower armatiufe and contact of relay 37, winding of relay 45, to ground. The second mentioned circuit will cause the relay 45 to operate, and thereby close a circuit from ground, through spring 61 of the interrupter M, conductor 62, lower contact and armature of relay 1-5, conductor 63, winding of relay 6 1, to grounded battery. An intermittent circuit will thus be provided by the interrupter, which opens and closes the armature of relay 64, and said armature upon opening and closing provides an intermittent current path from its upper grounded armature by way of condoctor 65, right hand normal contact of key 17, conductor 28, rheostat 18, conductor 27 resistance 26, conductor 25, left hand normal contact of key 17, conductor 66, make contact and armature of relay 15, conductor d6, upper back contact and armature of relay 4-7, armature and closed contact of relay 35, through the tip contacts of jack J and plug P and thence over a circuit through relay 1 as previously described. As formerly pointed out, the rheostat-18 may be adjusted by operating key 17 so that the above described testing circuit may have characteristics similar to those of an actual line. 1 7

Thus it will be apparent from the above descriptions that current may be applied intermittently to the direct current relay over a circuit of relatively low resistance and the'relay saturated in order that tests may bev made to insure that the armature Current of said relay will not stick up. may also he interin ttently applied to the direct current relay over a circuit of relativel y higher resistance, such as the resistance of an. actual line, andthe relay may thus be tested with an operating current such as would be met with under actual conditions. The intermittent application of current to these two testing circuits may be connected with jack J and plug P asso- I ciated with ack J The key K now op erated so as to restore any of the keys which may have been locked down during the previous testing. The depression of key K also closes a circuit from grounded battery 29, upper winding of relay 30, sleeve eonductor of the toll cord and sleeve contacts of plug P and ack J", sleeve contacts of Jack J and plug P closed contact of key K conductor 31, upper contactof key la conductor 33, tip contacts of plug P and ll 'd-f'l 68 f ae: r win ing 0 ie ay winning 0 marginal relay 37, conductor 38, windingol:

relay 39 to ground. This circuit will cause i relays 30, 68,37 and 39 to operate. Relay 07 upon operating will close a circuit from ground, over its upper cont-act and armature,conductor 67, winding of relay 4-7, to grounded battery; and the closing of this circuit will energize relay 47. The energization of relay 47 will close a circuit over its front contacts and armatures, over conductors 70 and 71, resistances 72, 73, 74c, 84c

and 85 and conductors 82 and 83, includ ing the back contact and armature of relay 75, It will be obvious from the foregoing description that the operation of relay 47 has resulted in the connection of the alternating current equipment of the adjusting circuit to the cord circuit instead of the direct current equipment previously de scribed.

The key K is now depressed and the following high resistance circuit closed: from battery 29, winding of relay 30,*sleeve con ductor of toll cord, sleeve contacts of plug P and ack J sleeve conductors of jack J" and plug P closed contact of key K conductor 31, resistance 32, lower make contact of key K conductor 76, upper make contact of key K resistance 77, ring contacts of plug P and jack J lower armature and 'flOlllZ'GOllllkLCl) of marginal .relay 37, which had been operated as previously outlined, conductor 79, through windings'of relays HO and 75, to ground. This circuit does not operate marginal relay 75, but relay 80 will operate at this time and attract its armatu'res. The energization of relay 80 will also provide-ringing current vfrom the source G, over conductors 82 and 83, resistaiic S4,

85, 7 2 and 73, conductors 70 and 71. front.

contacts and armatures of relay 4:7, con ductors 86 and 81, contactsand arinatures of relay 68, tip and ring contacts of ]2L(3l{ J and plug P through contacts of key 49 of the toll cord and over conductors 88 and windpress on oi. key b1 releases hey i alteruatii v K ot the test set should be depressed, and

relay :2 should be adjustedatter which the operation previously described may be repcated until said relay tinictions properly.

The lccy K should be depressed next and then licy ii should be operated. The do i" which was pro 'iously operated and COlllpltl'tGS a circuit through the windings oi relays (i3, 3? and 39 as formerly outlined, thus connectingm current generator G of the ad justing circuit to the toll cord The depression oi lre v K will complete a circuit trom grounded battery 52$) in the toll cord, winding: of relay 30, sleeve contacts or plug i and jack (i sleeve contacisoit' jack J and plug 1 contact ol key K, lower and upper contacts oi. hey K lower contact of key K", ring; contacts of plug P and jack J conductor 78, lower armature and make contact of relay 3'7. conductor 79, windings oit relays SO and T5 to ground. This circuit isiot lower resistance than the previously traced circuit, as the resistances 32 and 7'7 are not included therein, and will accordingly provide suiiicient current -tor the energization of relays 75 and 80. l. he operation of marginal relay 75 will cause its a rm aturc to be attracted, removing the shunt normally closed about the upper part of bridged inipedance 74, thereby increasing the impedance bridged across conductors 82 and 83. The increased impedance bridged across conductors S2 and 83 will decrease the current drain through the bridged impedance 74:, and therefore permit sufiicient current to flow over the previously traced circuit from generator G to relay 2 and the current now transmitted to said relay from generator G- will be equal to the operatingcurrent used under actual conditions and said relay should be energized. It the relay 2 responds to this current it is properly adjusted and upon operating will close the following; circuit: from grounded battery 29, armature and contact of relay 30, conductor 89 lamp 55 and relay 4: in parallel to the con tact and armature of relay 92, over conductor 93 to contact Del of key 95, winding of relay 96. conductors 9S and 57, tip contacts of jack 5 and plug P winding of relay 58, sleeve contacts of said plug and jack to ground. The relays 96 end 58 will be onergized by this circuit. Relay 96 will provide tor the lighting of lamp 9? by a circuit from through battery, filament of said lamp through contact and armature of relay 96 to ground, and relay 58 will provide for the lighting oi? lamp (50 ot tcst set T in a manner heretofore outlined. lhus the relays 96 and 58 and the lamps 97 and-60 will act in unison with each other. The lighting of lamp ($0 oi test set T under the above described tests will indicate that relay 2 is properly adjusted 'ior actual service conditions.

it sometimes happens that switchboardsequipped with various kinds of relays for which various adjustments must be made. For this purpose there may be pro vided a lamp jack 3* corresponding to lamp jack J. \Vhen it is desired to adjust one of these soecial type relays, plug P is asso ciated with the jack J and provision made for automatically selecting the correct bridged resistance values in the ringing network resistances for adjusting the special alternating current supervisory relays over the following circuit: From ground of lamp jack J, over conductor 99, winding of relay 100 to battery.

Relay 100 will be energized by this circuit and upon o peratinp; will associate the special resistance adapted for the correct adjustment of the special type oil? relay under test with the ringing network in an obvious manner.

it should be understood that the resistances used in the interrupter circuit and in the alternating circuit may be of such value or values that the current which flows through the circuit will be either the same as or somewhat less than the minimum, or

tions.

It will now be clear that by this invention a simple, convenient and efficient arrangement of circuits has been devised whereby any toll cord may be plugged into a convenient adjusting jack and the functioning oi? the various apparatus associated with the aid cord circuit may be determined by manipulating the keys associated with the test set. If any apparatus is found defective on such test, the cord with which the defective apparatus is associated may be controlled by the test set from a point adjacent to such apparatus and thereby the detective apparatus may be adjusted in a convenient and e'liicient manner.

While the invention has been disclosed as embodied in certain specific organizations and arrangements, it is to be understood that its embodiment may be varied without departing" from the spirit of the invention as definedin the following claims.

Having thus described the invention, what it is desired to secure by Letters Patent is:

1. A testing;- systcm comprising an operators cord circuit having a direct current relay and an alternating current relay, an auxiliary circuit associated with saidrelays,

a testing circuit adapted to be associated with said cord circuit comprising individual equipment for testing the direct and alternating current relays, a portable test set adapted to be associated with the testing circuit and auxiliary circuit, switching means in said set for selectively associating the direct and alternating current relays with their individual equipment, a relay in said test set operable upon such association, and signaling means in said test set controlled by said relay for indicating the operation of the direct and alternating current relays.

2. A testing system comprising an Open ators cord circuit, having a direct current relay and an alternating current relay, an auxiliary circuit associated with said relays terminating in a pair of lamp jacks, a test.- ing circuit-adapted to be associated with the cord circuit comprising individual equip ment for testing the direct and alternating current relays a portable test set, a pair of terminals for said test set one of which is adapted to be associated with the testing circuit and the other terminal with either of said lamp jacks, switching means in said test set for selectively associating the direct and alternating current relays with their individual equipment, a relay in said test set operable upon such association, and signaling means in said test set controlled by said relay for indicating the operation of the direct and alternating current relays.

3. A testing system comprising an operators cord circuit having a direct current relay and an alternating current relay, a testing circuit adapted to be associated with said cord circuit, direct current equipment in said testing circuit for testing the direct current relay, alternating current equipment of dif- :lerent resistance values in the testing circuit for testing alternating current relays of different operating values, an auxiliary circuit associated with the direct and alternating current relays terminating in a lamp jack, a second lamp jack associated with said auxiliary circuit and with the alternating current equipment, a portable test set, a terminal therefor connecting said test set with the testing circuit, a second terminal for said set adapted to be associated with either the first or second mentioned lamp jack, relay means associated with the alternating current equipment operable upon the connection of said second terminal with said second lamp ack for short circuiting certain of the resistances associated with said equipment, switching means included in the testing circuit for selectively associating the direct and alternating current relays with their individual equipment, a relay in said set operable upon such association, and signaling means in said set controlled by said relay for indicating the operation of the direct and alternating current relays;

4i. A testing system comprising an operators cord circuit having a direct current relay, an auxiliary circuit associated with said for associating the direct current equipment with the direct current relay for testing said relay, a relay in said test set associated with the auxiliary circiiit operable upon such test, and signaling means in said set controlled by the last mentioned'relay for indicating the operation and; acting in unison with the direct current relay.

5. A testing system comprising an opera tors cord circuit, having an alternating current relay, an auxiliary circuit associated with said relay, a testing circuit adapted to be associated with the said cord circuit, alternating current equipment simulating actual service operating conditions associated with the testing circuit, a portable test set adapted to be associated with the testing circuit and auxiliary circuit, switching means in said test set for associating the alternating current equipment with the alternating current relay for testing said relay, relay in said test set associated with the auxiliary circuit operable upon such test, and signaling means in said set controlled by the last mentioned relay for indicating the operation of the alternating current relay.

G. A testing system comprising an operatcrs' cord circuit having an alternating current relay, a testing circuit adapted to be associated with said cord circuit, alternating current equipment of diii'erent resist ance values in the testing circuit :tor testing alternating current relays oi? diii erent op erating values, an auxiliary circuit associated with the alternating current relay terminating in a lamp jack, a secoi'id lamp jack as sociated with. said auxiliary circuit and with the alternating current equipment, a portable test set, a terminal therefor for connecting said test setwith the testing circuit, a second terminal for said set adapted to be associated with the first or second mentioned lamp jack, relay means associated with the alternating current equipment operable upon connection of said second terminal with said second lamp jack for short circuiting certain of? the resistances associated with said equipment, switching means included. in the test tor associating certain resistance values in the alternating current equipment with an alternating current relay of certain operating value upon the connection of the second mentioned terminal of the test set with the tioned relay for indicating the operation of the alternating current relay under test.

In testimony whereof, I have signed my 10 name to this specification this 5th day of February 1920.

WVILLIAM H. HARRISON. 

